In order to allow a sensor to be rotated independently about two orthogonal axes, known gimbal designs are based on the general approach of having two concentric stages or cages each mounted on a separate set of bearings and actuators to control rotation about one axis, with the inner stage mounted on the outer stage to allow the sensor to rotate independently about the two orthogonal axes. Similarly, in order to allow a sensor to be rotated independently about three orthogonal axes, three stages are used, mounted successively on one another.
There are a number of problems with this approach. The large number of components makes known gimbal arrangements unreliable, expensive and complex to assemble. Further, the large number of components makes it difficult to scale down the gimbal for small sensors.
The present invention was made in attempt to overcome these problems, at least in part.